1. Field of the Invention
This invention relates to an improved method of bending the outer leads of a semiconductor device of QFP (Quad Flat Package) or SOP (Small Outline Package) type.
2. Description of the Related Art
In general, SOP and QFP type semiconductor devices have appearances such as are shown in FIGS. 1 and 2, respectively. The final configurations of outer leads of these semiconductor devices are formed by use of molds.
A conventional method of bending outer leads of a semiconductor device is as follows:
As is shown in FIG. 3A, a plurality of outer leads 2A and 2B protruding rightward and leftward from a resin 1 are simultaneously bent, thereby forming the final semiconductor device configuration as is shown in FIG. 3B.
The above method, however, has the following drawbacks:
The outer leads, before they are bent, have a variation c in the vertical direction relative to their root 3, the variation a resulting from contraction of the resin in a molding step or deburring. Since the variation in the outer leads 2A and 2B remains eve after they have been bent, the coplanarity of the final outer leads 2A' and 2B' is degraded and the final configuration is unstable.